1. Field of the Invention
The present invention relates to a high pressure method and apparatus for the treatment of aqueous or viscous fluids to destroy or otherwise render harmless undesirable living organisms in the fluids. A method and apparatus for removal of undesirable matter is also included.
2. Description of the Related Art
Various methods and apparatus are currently used for the treatment and/or removal of undesirable matter and organisms present in solution, in suspension or in a stable state of emulsion in aqueous fluids. Such methods typically suffer from drawbacks such as restricted flow and/or the inability to handle viscous materials such as sludge or slurries. Specific electrocoagulative treatment methods and apparatuses have been described in the literature. An example is U.S. Pat. No. 672,231 issued to Lacomme, which discloses the purification of water through the introduction of electricity, by a device applied to a section of a water main.
U.S. Pat. No. 3,969,245 issued to Ramirez discloses an electrocoagulation method and apparatus utilizing a cylindrical cell with concentrically positioned electrodes for electrolitically generating large quantities of gas bubbles while simultaneously flowing wastewater through the cell to form an embryo floc. The embryo floc subsequently attaches to the gas bubbles to achieve clarification by floatation. Ramirez vents the electrocoagulation cell to the atmosphere to avoid build up of pressure within the cell. One shortcoming of the Ramirez teaching is that current environmental standards dictate that fugitive air emissions are unacceptable and present complex permitting issues. Venting to atmosphere also limits applications in which an apparatus or process may be implemented due to hazardous materials venting to atmosphere and risk of explosion.
U.S. Pat. No. 5,928,493 issued to Morkovsky, et. al. relates to an electrocoagulation process and system for low pressure and low flow treatment of wastewater incorporating an agitated defoam tank utilized for allowing entrained gases to escape prior to entering a settling clarifier. The requirement of a defoam tank increases the overall footprint of the apparatus, adds additional plumbing and mixing components and vents off gases to atmosphere. This is unacceptable in many applications. The reactor cell housing of Morkovsky includes opposed grooved sides for retaining the electrode plates. This limits the application to low pressure conditions. Because of the spacing of the plates, when fluid velocities reach a critical point the differential pressure through the reactor cell is too great and the reactor cell is susceptible to leaking creating house keeping issues, exposure of possible hazardous materials to workers and the environment and the release of off gases to the environment. The Morkovsky reactor cell design is mechanically complex depending on “links” which are a means of connecting electrical power to the electrodes. These “links” must be inserted between the closely spaced electrode plates and tightened by means of nuts, screws and/or bolts and becomes maintenance intensive when exchanging the electrode plates or performing other maintenance.
German Patent Document DE 3641365 A1, issued to Klose discusses an electroflotation device for purification and treatment of polluted water by flowing the water over bundles of iron and aluminum electrode plates. Electroflotation is described as a combination of chemical and physical actions whereby iron and aluminum are sacrificed from the anodes and (as with chemical precipitation), utilized as an oxide for flocculation. Electrolytic action between anodes and cathodes release oxygen gases in the form of fine bubbles that enter into oxidation reduction reactions with substances in the water causing the precipitation of pollutants. Disinfection, metal removal and oil-water emulsion splitting occurs and contaminants are removed by vacuuming floated material from the surface and removing bottom sediments via the sloped bottom of the vessel. This device utilizes a rectangular tank, again open to the atmosphere, non-pressured and is not applicable to viscous fluids or sludges.
As illustrated by the background of the invention, attempts to develop methods and devices for the removal of contaminants from fluids have focused on low pressure electrolytic devices. It would be advantageous for an apparatus to accommodate high pressure and/or high flow during the treatment process of the sludge or other aqueous materials. It would be advantageous to cause undesirable matter to precipitate or co-precipitate from suspension and/or solution, destabilize suspended colloidal material, destabilize emulsions, or disrupt undesirable living organisms to treat fluid. It would be advantageous to use spacer plates to enclose and hold a variety of shaped electrodes while containing all fluids, electrical conduits and fluid conduits separately. It would also be advantageous for an apparatus to contain integral mixing chambers. A hydraulic mechanical closure means would also be advantageous. It would be advantageous to allow high pressure treatment of aqueous and/or viscous fluids while containing all fluids, fluid conduits, and electrical conduits within the boundaries of an apparatus isolating the fluids and conduits from the outside environment.